1. Field of the Invention
The present invention relates to a rooftop parapet for a building in which a plurality of thermally-insulated curtain walls is used to cover exterior building walls.
2. Prior Art
In modern buildings, curtain walls are widely used, partly because they enable a substantially reduced term of construction and partly because they make the building very neat in appearance.
As exemplified by FIG. 1 of the accompanying drawings, most curtain walls 1, each including a panel usually made of metal such as stainless steel, are secured to a building framework 2 by a plurality of fasteners 3 so as to be spaced apart facewise from the building framework 2. The uppermost curtain wall 1 has an upper part 1a which is spaced apart from a parapet base 4 with a gap s therebetween; a coping plate 5 is laid over an upper edge of the uppermost curtain wall 1, the gap s, and an upper edge of the parapet base 4. Because of this structural characteristic, the individual curtain wall 1 tends to become inwardly curved in its middle between the fasteners 3 when wind pressure acts on the curtain wall 1 (from outside), as shown in FIG. 2. At that time the upper part 1a of the uppermost curtain wall 1 is thus appreciably deflected away from the parapet base 4, widening the gap s. Consequently, the mounting of the coping plate 5 must be such that the coping plate 5 follows or allows such deflection of the upper part 1a of the uppermost curtain wall 1.
To effect a thermal insulation in such a rooftop parapet, it is known to place a thermally insulating material between the coping plate 5 and an upper edge of the parapet base 4, the curtain walls being thermally insulated. However, this thermally insulating material serves as an absorber of moisture inside the building, thus causing a sharply reduced degree of thermal insulation.